It is well known that hair is degraded by a number of environmental factors, such as sunlight and temperature extremes, factors which tend to dehydrate the hair, make it brittle, and cause the hair shafts to split or break. In addition, the hair may be degraded by waving it, bleaching or dyeing it, and also by abrading it while combing, toweling, etc. The resultant degradation manifests itself in disruption of the protective cuticle of the hair shafts, exposing the more vulnerable cortex. The observable result is dull, lifeless hair, lacking natural lubricity and luster, hair which is difficult to comb and style appealingly. Furthermore, the same factors which affect the hair shafts may also affect the scalp in such a way that growth of new hair is retarded.
The aforesaid problems are not new, and a number of cosmetic preparations, such as rinses, tonics, and hair conditioners in the form of aqueous or alcoholic solutions, or heterogeneous lotions and creams, have appeared over the years in attempts to alleviate the effects of such degradation. A number of such products are described, for example, in "Cosmetics--Science and Technology," 2nd Ed., Vol. 2, John Wiley & Sons, New York, N.Y., 1972, esp. pp 345-352.
In general, the hair conditions described in the past incorporate materials which are substantive to the hair or coat the hair shafts with a protective film; that is, materials which are sorbed onto or into the hair shafts and are not washed out easily, but which have a more or less longlasting effect. Once so sorbed, these materials restore lubricity to the hair and increase the diameter of the shafts, making the hair appear fuller, bulkier and easier to manage.
For example, U.S. Pat. No. 4,567,039 discloses a hair conditioning composition which incorporates an organosilicon quaternary ammonium halide which, in alkali, is shown to be substantive to the hair in that it cannot be washed off the hair readily. However, the organosilicon compound is unstable in alkaline solution, so the composition has a short shelf life and must be constituted just prior to use.
U.S. Pat. No. 4,584,191 described hair/skin care compositions containing lower alkyl esters of biotin, vitamin H. These esters are said to be sorbed by the hair and skin more effectively than biotin itself and then converted into biotin in vivo. Biotin is known to be a growth factor present in minute amounts in every living cell.
Hair conditioner formulations containing a prescribed ratio of d-panthenol and d-panthenyl ethyl ether are disclosed in U.S. Pat. No. 4,705,681. Such formulations, when applied to hair, are said to decrease the friction between individual shafts and thereby lessen the abrasion damage when the hair is combed or brushed.
Whereas the hair treatment and conditioning compositions of the prior art are directed to ameliorating the damage done to hair by the environmental and other factors mentioned above, there is a need for new and more effective hair enrichment agents, especially hair enrichment compositions which address the damage caused by the aforesaid factors, not only to the hair shafts, but also to the scalp.
Thus, it is one object of this invention to provide a one-part hair enrichment composition which is stable and exhibits good shelf life. It is another object to provide a hair conditioning composition which not only treats the damaged shafts of hair, but which also enriches and invigorates the scalp.